Expansion Ring For Eyeball Tissue

ABSTRACT

A length or strand of resilient material is formed into a continuous ring having multiple tissue-engaging portions for engaging and spreading eyeball tissue segments apart. The strand is formed with elongated straight sides joined by corner portions which are enlarged in directions transverse to the length dimension of each adjacent side. The corner portions constitute the tissue-engaging portions and have top and bottom sections and a connecting section that forms a gap for receiving the tissue. Each side of the ring extends from a bottom section of one corner to a top section of an adjacent corner. When the ring is deployed, the tissue is captured in the gaps at the corners of the ring and also is engaged along each side as that side transitions from a position situated below the tissue to a position situated above the issue.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/568,857, filed Jan. 5, 2022, which is a continuation of U.S.application Ser. No. 16/729,034, filed Dec. 27, 2019, now issued as U.S.Pat. No. 11,219,438, which is a continuation of U.S. application Ser.No. 15/925,308, filed Mar. 19, 2018, now issued as U.S. Pat. No.10,517,582, which is a continuation of U.S. application Ser. No.13/466,968, filed May 8, 2012, now issued as U.S. Pat. No. 9,918,710,which is a continuation-in-part of U.S. application Ser. No. 13/291,946,filed Nov. 8, 2011, which claims the benefit of U.S. ProvisionalApplication 61/411,870, filed Nov. 9, 2010, and said U.S. patentapplication Ser. No. 13/466,968, filed May 8, 2012, is acontinuation-in-part of U.S. application Ser. No. 12/074,731, filed Mar.5, 2008, which claims the benefit of U.S. Provisional Application No.60/918,404, filed Mar. 15, 2007. The entire teachings of the aboveapplications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a ring used to maintain an opening ineyeball tissue in an expanded condition during an ophthalmic procedure.

During ophthalmic surgery, it is sometimes desirable to enlarge anopening in eyeball tissue, such as holding the iris open for accessthrough the pupil. For example, cataracteous lenses can be replaced in aprocedure commonly referred to as phacoemulsification, or “phaco” forshort. In a phaco procedure access through the pupil is required toinsert and manipulate an ultrasonically driven tool to break apart andaspirate the lens. It has been proposed that, at least in some cases,expansion of the opening be achieved mechanically by hooks that engageand pull against edge portions of the eyeball tissue, such as inner edgeportions of the iris to expand the pupil during a phaco procedure. See,for example, the hooks disclosed in U.S. Pat. No. 5,716,328.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features ofthe claimed subject matter, nor is it intended to be used as an aid indetermining the scope of the claimed subject matter.

The present invention provides a length or strand of resilient materialformed into a continuous ring having multiple tissue-engaging portionsfor engaging and spreading eyeball tissue segments apart. The strand isformed with elongated straight sides joined by corner portions which areenlarged in directions transverse to the length dimension of eachadjacent side. The corner portions constitute the tissue-engagingportions and have top and bottom sections and a connecting section thatforms a gap for receiving the tissue. Each side of the ring extends froma bottom section of one corner to a top section of an adjacent corner.When the ring is deployed, the tissue is captured in the gaps at thecorners of the ring and also is engaged along each side as that sidetransitions from a position situated below the tissue to a positionsituated above the issue.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description, whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an enlarged, diagrammatic top perspective of an expansion ringin accordance with the present invention;

FIG. 2 is a further enlarged, fragmentary detail thereof;

FIG. 3 is a diagrammatic top plan thereof;

FIG. 4 is a diagrammatic top plan thereof corresponding to FIG. 3 butwith parts in different positions;

FIG. 5 is a diagrammatic side elevation thereof;

FIG. 6 is an enlarged, fragmentary detail of a corner portion thereofviewed generally in the direction indicated by the arrow A6 in FIG. 1and showing such corner portion in elevation looking toward the centerof the ring;

FIG. 7 is an enlarged, fragmentary detail of such corner portioncorresponding to FIG. 6 but showing such corner portion in an obliqueorientation; and

FIG. 8 is a perspective of an injector and ring holder that can be usedto load and inject the ring, with some parts shown in explodedrelationship;

FIG. 9 is a diagrammatic top plan of a modified expansion ring inaccordance with the present invention;

FIG. 10 is a diagrammatic top perspective thereof during manufacture;

FIG. 11 is a diagrammatic top perspective of manufacturing equipmenttherefor;

FIG. 12 is a diagrammatic section of the manufacturing equipmenttherefor;

FIG. 13 is a diagrammatic top perspective of equipment for insertionthereof;

FIG. 14 is a diagrammatic top perspective of equipment for insertionthereof corresponding to FIG. 13 but with parts in different positions;

FIG. 15 is a diagrammatic top plan illustrating insertion thereof; and

FIG. 16 is a diagrammatic top plan illustrating aspects thereof afterinsertion.

DETAILED DESCRIPTION

In the embodiment of the present invention shown in FIG. 1 , acontinuous ring 10 is formed from a single long strand of resilientmaterial, such as a molded plastic material. In the illustratedembodiment, the ring 10 has four corners 12, 14, 16, and 18 connectingfour straight sides 20, 22, 24, and 26. As described in more detailbelow, each corner is formed by a loop of the strand. Although a squarering is illustrated, it is to be understood that the ring may have arectangular configuration, or a nonrectangular shape. For example, thering may be formed as a triangle that has three sides and three loopslocated at the ring corners, as represented by the broken line in FIG. 1representing a triangular ring having corners 12, 18, and 14.

FIG. 2 shows a preferred construction in which the ring is formed fromone length of material with two ends 30 and 32 that are “butt attached”by adhesive represented at 34. Each of the ends 30 and 32 has an indent36, 38, respectively, such that the adhesive 34 can flow into theindents to increase the strength of the butt attachment. The indentscreate surface structure that minimizes shearing and de-lamination ofthe adhesive 34 from the ring 10. A representative adhesive is a ClassVI epoxy, applied by a tool that ensures a repeatable volume anddimension of the solidified adhesive form.

With reference to FIGS. 3-5 , the ring 10 can be drawn into an insertiontube T and, after insertion of the tube into the posterior chamber ofthe eye, projected from the tube and manipulated to expand the openingof the iris. FIG. 3 shows the initial stages of the ring 10 beinginserted into the pupil P. The corner loop 18 remote from the tube ismanipulated to capture an edge portion of the iris. Corners 12 and 16 atthe sides form deflection areas or “hinges” between the sides adjacentto them. With reference to FIG. 4 , as the ring is inserted farther itcan be manipulated so that iris tissue is received in such side loops 12and 16. As seen in FIG. 5 , each corner loop has a gap 58 that receivesand captures iris tissue. The loop design provides an easy means ofinserting and capturing iris tissue.

More specifically, FIG. 6 is an enlarged elevation view looking inwardtoward the center of the ring at corner 12, and FIG. 7 is acorresponding view but at an oblique angle from a higher viewpoint.Although corner 12 is referenced, all four corners are identical, asshown in the drawings. Each corner connects two adjacent straight sides,each long and narrow and elongated in the direction of its length (whichcan be referred to as the “x” dimension). For corner 12, the adjacentsides connected are side 20 which is inclined up from the bottom ofcorner 18 (see FIG. 1 ) to the top of corner 12. Similarly, side 22 isinclined away from the bottom of corner 12 to the top of corner 14 (FIG.1 ), and so on around the ring. Each side extends from the bottom of onecorner to the top of another, and each corner is enlarged in a firstdirection transverse to the x dimension of a side it connects (which canbe referred to as the “y” dimension; vertical in the orientation of FIG.6 ). The broken line L in FIG. 6 represents the location of theoutermost point of the corner where the widest part of the gap 58 islocated (and where the corner is presented to the tissue to becaptured). From line L the corner loop has an arcuate section 59 thatspirals down and to the inside of the ring like a single loop or coil ofa helix. As compared to the x and y dimensions, the inward direction canbe referred to as the “z” dimension (which is into the page in theorientation of FIG. 6 , and which is orthogonal to the y dimension). Thecorner is enlarged in the y and z dimensions as compared to the narrowheight and width of a side. As seen in FIG. 6 , the inner part of thesection 59 will extend diagonally along the edge of the tissue capturedin the gap 58 resulting in a broad contact area at the edge of the iris,for example. The gap 58 can be proportioned such that there is aclamping force applied to the iris tissue captured in the corner loop.

As represented diagrammatically in FIG. 4 , the iris is expanded furtheras the ring is inserted and the corners capture the edge of the iris andspread it open, providing a larger space for an ophthalmic procedure tobe performed.

FIG. 8 shows an embodiment of an injector 100 that can be used to injecta ring 10 into a patient's eye. The ring can be loaded into the injectorwith the use of a holder 102. The holder 102 may include a cover 104that is attached to a base plate 106 by fasteners 108. The base plate106 has a channel 110 and a recess 112. The recess 112 receives the ring10.

The injector includes a cannula 120 attached to a handle 122. Within thecannula 122 is a wire hook 124. The wire hook 124 is connected to aninner slide tube 126 located within the handle 122. A button 128 isattached to the inner slide tube 126. The injector 100 may also have apair of guide pins 130 that are attached to the handle 122 and cooperatewith the corresponding channel features 132 of the base plate 106 toproperly align the injector 100 when the cannula is inserted into thebase plate channel 110.

In operation, the cannula 120 is inserted into the base plate channel110. When fully inserted the wire hook 124 extends into the ring 10. Thecover 104 may have an opening that allows an operator to visually seethe hook 124. An operator pulls the button 128 in the directionindicated by the arrow. Pulling the button 128 causes the hook 124 tograsp the ring at a corner loop and pull the ring into the cannula 120.The recess 112 has tapered walls 136 to assist in the ring collapsingwithin the channel 110 for insertion into the cannula 120. Once loaded,the ring 10 can be injected into a patient's eye by pushing the button128 in the opposite direction.

FIG. 9 shows a modified iris extension ring 60 in accordance with thepresent invention. It should be noted that in FIG. 9 , and all drawings,sizes are exaggerated for ease of illustration and understanding. Ring60 is formed from a single long strand of resilient material such as 4-0or 5-0 polypropylene surgical suture. The ring material has memorycharacteristics such that when held taut in a desired shape and thenheat treated and cooled, such shape will be retained in the relaxed or“at rest” state. Due to the resiliency of the material, from the relaxedstate the material can be deformed, in which case it applies a resistingforce tending to return to the preformed shape.

In the case of the embodiment of the present invention shown in FIG. 9 ,ring 60 has four straight sides 62, 64, 66, and 68. Side 62 has the endbutt joint 70 where a drop of adhesive 72 secures the ends 74, 76, suchends preferably having the indented portions 78 to increase the holdingeffectiveness of the adhesive.

In the plan view of FIG. 9 , side 64 is perpendicular to side 62. Thesesides are joined by a corner portion 63 which has three distinct bends,namely, a first obtuse bend 80 (essentially 135° inward and to the leftas viewed in FIG. 9 ), a second return bend 82 (essentially 180° inwardand then down away from the viewer and then toward the right as viewedin FIG. 9 ), and a third obtuse bend 84 (essentially 135° up and to theleft as viewed in FIG. 9 ). Corner 65 joining sides 64 and 66 isidentical to corner 63 with the three distinct portions 80, 82, 84, asare the two additional corner portions 67 (joining sides 66 and 68) and69 (joining sides 68 and 62).

The shape of the ring embodiment 60 can be achieved by use of a windingfixture, aspects of which are shown diagrammatically in FIG. 10 . Thefixture includes a composite jig having a thin plate 100 with fourgenerally radially extending arms 102 spaced 90° apart. Vertical pins104 extend upward through holes in the outer end portions of the arms102 at locations corresponding to the obtuse bends 80. The end portionsof the arms 102 also have short tabs 106 curved down from the plane ofthe remainder of the plate 100, approximately aligned with the pins 104.

Aspects of the ring 60 may be better appreciated in conjunction with themanner in which the ring is manufactured. Starting at the left of FIG.10 , a length of the suture material S is stretched to the lowermost pin104 and wound around the outer periphery of the pin to achieve theinward obtuse bend 80 of approximately 135° for the corner portion 63.From there the suture extends along the top of the plate 100 to theinner edge of the associated tab 106, then down under the plate and backoutward to form the inner bend 82 of approximately 180°. This section ofthe suture extends along the face of the tab adjacent to thecorresponding arm 102 and then along the outer edge of tab and towardthe next pin 104 to form the last obtuse bend 84 of corner portion 63.Thus, there is a short stretch of suture that extends almost radiallyalong the face of the tab and the obtuse bend 84 which leads to the side64. The winding procedure is the same at corner portions 65, 67, and 69,with the opposite (“exiting”) end portion S′ of the length of sutureextending to the right as seen in FIG. 10 , along side the enteringportion S.

FIG. 11 shows the winding fixture on a smaller scale (dimensions stillexaggerated due to the extremely small nature of the ring, particularlythe suture which may be on the order of 0.006 to 0.008 inch diameter).Plate 100 is mounted on a central hub 110 fixed to an upper elevatorblock 112. Block 112 is guided for vertical movement by bolts 114 andthe pins 104 that extend somewhat loosely through the elevator block 112to a base block 115. An entrance screw 116 is provided to anchor thestretch of suture that leads to the winding pins, and an exit screw 118is used to anchor the opposite or exiting end portion of the sutureafter the winding operation is completed (i.e., after the suture isrouted as shown in FIG. 10 ). With the suture thus held in the desiredform, it is heated in an oven to close to the softening temperature fora period of time sufficient to achieve the desired memorycharacteristics. In a representative embodiment, the heat treating canbe at a temperature of 165° C. to 170° C. for 6 to 8 minutes, but thetemperature and time may be adjusted depending on the particularmaterial used. Thereafter, the fixture and iris extension ring containedthereon are cooled.

With reference to FIG. 10 , after cooling, the entering and exitingstretches of suture can be severed in one snip, preferable approximatelymidway between the adjacent corners, such as at the location indicatedby the broken line L′ in FIG. 10 . Then, as represented in FIG. 12 , theupper elevator block 112 is raised such that the winding plate 100 islifted to a position above the tops of the pins 104, which simplifiesremoval of the ring 60 from the fixture, prior to completion of the ringby joining the cut ends as previously described.

With reference to FIG. 13 , a single completed ring 60 can be fitted ina recess of a holder having a bottom section 120 and lid section 122.Such holder has a channel leading to the recess in which the ring 60 ispositioned, for reception of the insertion tube 124 of an implantinginstrument 126. FIG. 14 illustrates the parts connected with theinsertion tube received in the channel.

FIG. 15 illustrates ejecting of the ring 60 in the eye, with the innerbend 82 of corner portion 65 engaged against an edge portion of theiris. Such edge portion rides into the gradual arc of bend 82 withlittle or no friction that could cause abrasion. Each corner is enlargedin two directions transverse to the length (x dimension) of each narrowstrand side that it connects. One transverse direction (y dimension)forms the gap or opening presented to the tissue to be captured. Theother transverse direction (z dimension) extends inward and limits theextent of insertion of the tissue into the channel or pocket formed bythe inner portion (bend 82 for this embodiment) of the corner. FIG. 16illustrates the position after the ring 60 has been fully deployed. Theinnermost bend 82 of each of the corner portions receives a portion ofthe inner edge of the iris. The ring is sized such that it is in aslightly compressed state when deployed, so that an expansion force isapplied against the iris to increase the opening. Also, it can be seenin FIG. 16 that the bends 82 do not apply the only edge-contactingportions of the ring. A top obtuse bend 80 at each corner leads to thecorresponding return bend 82. Such return bend 82, in turn, leads to abottom obtuse bend 84 (shown in broken lines). The side to which abottom obtuse bend 84 leads is inclined upward (outward) slightly due tothe positioning of the suture on the winding fixture, just as thestraight sides of the previously described embodiment transition fromthe bottom of one corner to the top of the next, and each side of thering emerges from the pupil approximately midway between adjacent bends(or corners), or at least somewhat centrally between the bends. Thus,there are eight spaced points of contact of the iris edge portion by thecontracted ring 60 (or ring 10) for a more even application of anexpanding force.

As seen in FIG. 16 ring 60 can be formed with no parts of any cornerthat directly overlie one another. The dimensions of the ring and thevarious bends are chosen so that minimal abrasive force is applied tothe iris, and no or essentially no pinching or clamping force. However,the bends 82 do not extend diagonally across the inner edge of the irisas in the previously described embodiment. Dimensions are selected suchthat the opening formed by each return bend 82 is at least as great asthe marginal thickness of the iris, with no coils or loops located oneabove the other.

More specifically, it can be seen in FIG. 10 that each obtuse bend 80(best seen for the bend 80 at the top of the view) is angled outwardslightly from its pin 104 to the corner between the plate arm 102 andthe corresponding tab 106 where the central portion of the return bend82 is formed. The bottom part of such return bend is canted slightlyaway from the top part of the bend to the outer edge of the tab. Theradius of curvature of the return bend is determined primarily by thethickness of the plate 100. In a representative embodiment, the platecan be 0.015″ thick. It has been found, however, that the total depth ofthe channel or notch formed by the return bend will be somewhat greaterthan the plate thickness, such as 0.019″ to 0.020″ in a representativeembodiment.

While illustrative embodiments have been illustrated and described, itwill be appreciated that various changes can be made therein withoutdeparting from the spirit and scope of the invention.

What is claimed is:
 1. An expansion device for eyeball tissue comprisinga strand of resilient material having multiple tissue-engaging portionsfor engaging and spreading eyeball tissue segments apart, said strandbeing formed as a continuous ring with straight sides joined by cornerportions, said corner portions constituting the tissue-engagingportions, each corner portion having a top section, a bottom section,and a connecting section of the strand extending between and joining thetop section and the bottom section and forming a gap therebetween forreceiving an edge portion of an eyeball tissue segment, each sideextending from a bottom section of a first one of the corner portions toa top section of a second adjacent one of the corner portions, whereby,when the ring is deployed with an edge portion of an eyeball tissuesegment captured in the gaps of adjacent corner portions, the side thatextends between said first and second corner portions transitions acrosssuch edge portion.
 2. The device defined in claim 1, in which the ringis sized for engagement of the inner edge of an iris in the gaps of thecorner portions to hold the iris in an expanded open condition andenable access therethrough during an ophthalmic procedure.
 3. The devicedefined in claim 2, in which the connecting section of each cornerportion forms an outward opening channel for reception of an inner edgeportion of an iris.
 4. The device defined in claim 3, in which theconnecting section of each corner portion is arcuate.
 5. The devicedefined in claim 4, in which the connecting section of each cornerportion is a single loop spiraled inward from adjacent sides of thering.
 6. The device defined in claim 5, in which the loop is helical. 7.The device defined in claim 5, in which the loop has overlappingportions at an outer edge portion of the corner portion to overlie andunderlie the inner edge of an iris, respectively.
 8. The device definedin claim 4, in which the connecting section of each corner portion is a180 degree return bend forming a concave channel for reception of anedge portion of an iris.
 9. The device defined in claim 3, in which theconnecting section of each corner portion has an upright inner portionlimiting insertion of an iris edge segment in the channel.
 10. Thedevice defined in claim 9, in which the upright inner portion of theconnecting section extends diagonally across an edge portion of an iriswhen received in the channel.
 11. The device defined in claim 9, inwhich the upright inner portion of the connecting section does notextend diagonally across an edge portion of an iris when received in thechannel.
 12. The device defined in claim 2, in which the strand is alength of plastic material having opposite ends joined together to formthe continuous ring.
 13. The device defined in claim 12, including adrop of adhesive holding the opposite ends together.
 14. The devicedefined in claim 13, in which each of the opposite ends has an indentedportion, the adhesive filing the indented portions and encircling theopposite ends adjacent to the indented portions.
 15. The device definedin claim 12, in which the strand is a length of surgical suture havingopposite ends joined together to form the continuous ring, each of theopposite ends having an indented portion, and including a drop ofadhesive filing the indented portions and encircling the opposite endsadjacent to the indented portions.
 16. The device defined in claim 1, inwhich the sides are of equal length.
 17. The device defined in claim 1,in which the ring is square.
 18. The device defined in claim 1, in whichthe ring is triangular.